Yes, Mandrake is a "Full" operating system, meaning that you can install it and it will be similar to windows in a general computing sense.
When you boot from the Mandrake CD it will allow you to create a new partiton for it. In fact, it will probably automatically get it set up for you so that all you have to do is hit "Okay". The only way that you will lose Windows is if you accidentally delete the Windows Partition. A word of caution: always back up anything that you would not want to lose.
Mandrake is a distribution of Linux. It is a very popular distro for new Linux users. You will find that it is very user friendly. Good choice
Don't be afraid to ask any questions